Life, Peter Boyle as Wizard from Taxi Driver (1976)

Look, look at it this way, you know uh, a man, a man takes a job, you know, and that job, I mean like that, and that it becomes what he is. You know like uh, you do a thing and that's what you are. Like I've been a, I've been a cabbie for seventeen years, ten years at night and I still don't own my own cab. You know why? 'Cause I don't want to. I must be what I, what I want. You know, to be on the night shift drivin' somebody else's cab.

- Peter Boyle as Wizard from Taxi Driver (1976)

---

http://en.wikiquote.org/wiki/Taxi_Driver

AFI #010 Robert De Niro as Travis Bickle from Taxi Driver (1976)

Yeah. Huh? Huh? Huh? (I'm) faster than you, you fuckin' son of a...I saw you comin', you fuck, shit-heel. I'm standin' here. You make the move. You make the move. It's your move. [He draws his gun from his concealed forearm holster] Don't try it, you fucker. You talkin' to me? You talkin' to me? You talkin' to me? [He turns around to look behind him] Well, who the hell else are you talkin' to? You talkin' to me? Well, I'm the only one here. Who the fuck do you think you're talkin' to? Oh yeah? Huh? OK. [He whips out his gun again] Huh?

- Robert De Niro as Travis Bickle from Taxi Driver (1976)

The bolded line is ranked #10 in the American Film Institute's list of the top 100 movie quotations in American cinema.